core: Append source ID in media_from_uri operation
core: Append source ID in media_from_uri operation

If the source resolving the URI does not add the source-id, let's do it in the
core instead.

We always want the media coming with the source-id.

MathieuDuponchelle/grilo,MathieuDuponchelle/grilo,MathieuDuponchelle/grilo,grilofw/grilo,GNOME/grilo,GNOME/grilo,jasuarez/grilo,jasuarez/grilo,grilofw/grilo,jasuarez/grilo,grilofw/grilo